Patent publication CN1916474A discloses a releasable plug-in connector (removable plug-in connector) for inserting a tubular insert having a peripheral flange. This connector includes a cylindrical insertion chamber housing that receives the insertion of a tubular insert and a separate locking ring (self-locking device) made of a rigid/elastic plastic. The locking edge of the ring is inwardly in a circular arc shape. When the tubular insert is pushed into the connector, the arc-shaped edge is pushed apart, and then the insert is pushed into and locked to the element in the connector, the arc-shaped edge is rebounded and engaged with the flange. The distal ends of the locking edge are connected to each other by a pair of V-shaped elastic arms, and the elastic arms are accessible from the outside of the connector housing to push them into the unlocked position to pull the insert from the connector.
Patent document CN1751202A discloses a quick connector dust coyer and a quick connector (removable plug connector) that cannot lock a stopper (self-locking device) as long as a dust cover is inserted. An O-ring protector and an interference part that interferes with a part of a stopper (self-locking device) are integrally provided on the cylindrical dust cover body, and the dust cover body is inserted into the shell of the quick connector. In the body, the O-ring is externally fitted on the O-ring protector, and the interference portion restricts the stopper (self-locking device) to a position where it cannot be locked.
The complexity of the self-locking structure of the existing detachable plug-in connector is very inconvenient to install.